Cutter



C. E. KRAUS Sept. 6, 1955 CUTTER Filed June 1 1952 I? la so INVENTOR. (54441 EM United States Patent O This invention relates to metal removing tools or outhas aving ndi d a y p c abl la It is an object of my present invention to provide a new and improved cutter of the inserted or replaceable blade type, such as that shown in my prior United States Patent 2,407,501 issued on September 10, 1946, i; and which is simple, inexpensive and readily substituted for aged o Wa n u blade Another object of my invention is to provide a new and improved detachable blade adapted for mounting on a suitable body or supporting member and which 51- is of such nature that a maximum number of blades may be assembled on a given body or a given number of blades may be assembled on a body of minimum size.

Still another object of my invention is to provide new and improved means for mounting replaceable blades 1,

which insures rigidity of mounting of the blade on the tool body.

Other objects and advantages of my invention will become apparent from the following detailed description taken in connection with the accompanying draw- 52.

ing, in which Figure 1 is an end view of an assembled cutter embodying the features of my invention, Figure 2 is a side view of the cutter shown in Figure 1, Figure 3 is a top view of a blade such as that shown in Figures 1 and 2, and Figure 4 is a sectional view taken along the line 4-4 of Figure 3.

While the invention is useful with various types of cutters for carrying out different metal-removing processes, it has been illustrated as embodied in a rotary milling cutter comprising a body in the form of a generally fiat ring 10 and a plurality of separately formed blades 11 annularly spaced around and detachably secured against mounting surfaces 12 on the outer periphery of the body. The latter is made of any suitable material, such as steel or cast iron, for example, and is formed with the usual hub 13 which may be centrally recessed as shown so that it may be mounted on and keyed to a spindle or arbor in the usual way. The blades 11 may be made entirely of cutting material such as high speed steel, or, as shown, they may be of ordinary steel and formed at one end with recesses 14 for receiving tips 15 of carbide or other cutting material seated in and bonded or otherwise suitably secured to the walls defining recesses 14.

Except for the width and inclination of their cutting faces, blades 11 may be of the same construction for various kinds of cutters. Each blade comprises a blank of metal having a flat bottom surface 16 and a top surface 17, at least the rearmost or trailing portion of which converges toward the bottom surface in the direction of the tail end 18 of the blade. The end 18 has spaced-apart fiat portions 18a, the overall width of the body 11 at the tail end being substantially equal to the thickness of body 10. End 18 extends transversely of bottom surface 16, the flat portions 18a intersecting bottom surface 16 at an acute included angle and the top surface 17 at an obtuse angle.

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' ing 36.

2,716,801 Patented Sent- 6, 1955 "ice The other or leading end of the blade is shown wider radially and'tip 15 defines a cutting face 19 terminating in, end and side cutting edges 23 and 20, respectively, and inclined at the rake and shear angles desired to be imparted to the cutting edges. Blades 11 are preferably enlarged or made thicker toward the leading end. In the illustrated form of my invention, this enlargement is in the form of a uniform taper symmetrical with the longitudinal center line of the blade, the sides of the blade diverging gradually from the rear end t ward, the u t o o rd and he tap su face of the blade adjacent the cutting tip 15 is shaped to provide proper clearance for the peripheral cuttirig edge 23. Similarly, the sides of body 11 and tip 15 are finished to provide suitable clearance for cutting edges 20. The tapering sides and converging top. and bottom surfaces of blade 11 provide chip receiving re,- cesses between successive blades, in advance of the gut,- ting face or edge of the next adjacent blade.

In accordance with the present invention, each blade 11 is ea d on e Per p o bo 1 th t e tai end portions 18a against an abutment 24 which is shown nt al with bod 0 n w i u t s th forces that are exerted on the blade in the plane of rotation at b e- To this end, nhu a l s d RI;, 9 .1. .1 e bur e cu away, as y e milline 9 arm the flat hq da u c 12 intersecting at 99 sad w th. abu me t 2.4 t P e is y th ame hgle tha tai end 18 of the blade 11 forms with bottom surface 16. The abutment is preferably the same radial height at blade end 18.

Means is provided for maintaining each blade 11 firmly against its seat 12 and also abutment 24. In the present invention, this means comprises a suitable threaded fastening member such as a cap screw 27 projecting through hole or opening 28 in the blade and threading into tapped hole 29 in disk or body 10 and a suitable locating member or pin 30 projecting through slot or recess 31 between tail surfaces or portion 18a into body 10. The hole 29 which extends perpendicularly to the blade and body surfaces 16 and 12, respectively, is located accurately with respect to blade end 18 and abutment 24 in order to obtain full contact between the blade and the abutment when the blade is fastened to the body. To insure that such full contact is obtained, blade hole 28 is preferably counterbored at the upper end as indicated by numeral 32 to provide a conical seat 33 which cooperates with mating surface 34 at the lower end of the cylindrical screw head 35 to cam the blade against the abutment as the screw is tightened. Hole 28 and the counterbore is preferably made slightly larger than the screw to permit of this action which compensates for any slight inaccuracy in the location of the screw holes relative to the abutment.

To assist further in the accurate positioning of blades 11, pin 30 is so dimensioned that at least the adjacent surfaces of end portions 18a partially defining recess or slot 31 engage opposite sides of pin 30. Recess 31, spaced rearwardly from hole or opening 29, may be made deep enough to allow a certain amount of leeway in the longitudinal positioning of blade 11 as best seen in Figures 3 and 4. Pin 30 may be staked or threaded or otherwise secured in a suitable open- Instead of a recess 31, any suitable opening may be provided such as a longitudinally elongated slot, for example.

With the blade seated and fastened to the body in the manner described above, the mounting is extremely rugged and well adapted to sustain the forces of tip 15 positioned at widely varying rake and shear angles. The tangentially directed thrusts on the blade are sustained mainly by the abutment 24 and are directed along a line generally parallel to the bottom surface 16 of the blade. Tipping of the blade by this force is prevented by screw 27, and screw 27 and pin 30 serve to sustain the side thrusts on the blade. The ability of the blades to withstand such side forces is increased by locating seat 34 close to bottom surface 16, thereby minimizing any possible deflection of the screw under the thrusts of the blade. The open-ended recess and pin arrangement enables the use of blades substantially shorter than prior art blades so that more blades may be provided on the periphery of a body of a given diameter, or a given number of blades may be assembled on a smaller body than possible hitherto. Moreover, by providing symmetrical blades, a saving in inventory is achieved because only one blade shape need be stocked What I claim is:

I. In a cutter blade of the type comprising a block of material having opposite fiat ends, a fiat bottom surin face and a top surface generally converging toward said bottom surface in the direction of one of said ends, the latter constituting an abutment surface disposed at an acute included angle to said bottom surface, the other end of said block providing a cutting face projecting from at least one side of said block; a hole extending through said block at right angles to said bottom surface for receiving a fastening member, and said blade having an opening spaced rearwardly from said hole and extending inwardly from said abutment sur- 1;

face and through said block at substantially right angles to said bottom surface for receiving a pin for locat' ing laterally said block, said abutment surface and said fastening member constituting additional means for enabling the securing of said block to a suitable support.

2. in a tool of the type comprising a body having a fiat blade seat thereon and a rigid abutment upstanding from said seat at one end thereof and disposed at an acute included angle with respect to the seat, a blade having a flat bottom resting on said seat and a tail end contacting said abutment, the top of said blade gencrally converging toward said bottom surface in the direction of said abutment, said body extending from said seat beyond the other end of said blade and shaped to fully expose the latter end, a cutting member on said other blade end; means for securing said blade to said seat comprising a screw projecting through the blade and into said body intermediate the ends of said blade in order to clamp said blade against said seat, said upstanding abutment and said tail end being arranged to prevent movement of said tail end away from said seat, said blade having an opening spaced rear- Wardly from said screw and extending inwardly from said tail end, and a pin projecting through said opening and into said body in the vicinity of said one end in order to locate said tail end with respect to said body.

References Cited in the file of this patent UNITED STATES lA'lENTS 2,407,501 Kraus Sept. 10, 1946 FOREIGN PATENTS 878,004 France Jan. 8, i943 

